Bump utils to 21.0.0
Bump utils to 21.0.0

This changes the log file handler to WatchedFileHandler which should
successfully handle different processes writing to the same logrotated
file.

gov-cjwaszczuk/notifications-admin,gov-cjwaszczuk/notifications-admin,gov-cjwaszczuk/notifications-admin,alphagov/notifications-admin,gov-cjwaszczuk/notifications-admin,alphagov/notifications-admin,alphagov/notifications-admin,alphagov/notifications-admin